Unified Modeling Language Reference Manual, The, Second Edition

redefinition (state machine)

In specializing a classifier, the behavior state machines specifying the classifier and its methods may be redefined. (The document uses the word extended in referring to redefinition of state machines.). When a state machine is redefined, its states, regions, and transitions may be redefined.

States may be redefined. A simple state can become a composite state by adding a region. A composite state can add regions, vertices, transitions, entry/exit/do activities, and transitions to regions inherited from the original state machine. If a state is part of a region, a redefinition of the state must be part of a redefinition of the region. A redefinition of a submachine state can replace the submachine reference, provided ...